The circumstances of Malaysia Airlines Flight 370—with its lack of physical evidence and numerous potential jurisdictions—are likely to make legal action especially complicated for families seeking compensation in the courts.

Regardless of what caused the plane's disappearance, family members of the passengers and crew can bring legal action against Malaysia Airlines for compensation, legal experts say. One U.S. law firm has already filed a petition in a U.S. court on behalf of the relative of a Flight 370 passenger...